Dehydrogenation is a chemical reaction that involves the elimination of hydrogen (H2) and is used in large scale industrial processes or smaller scale laboratory procedures. Copper is a known catalyst for dehydrogenation reactions, however, the activity and selectivity of the catalyst can be significantly enhanced by the correct use of promoters as well as the correct method of preparation of the catalyst. Zinc oxide (ZnO), zirconium oxide (ZrO2) and aluminum oxide (Al2O3) have been used as components with various Cu-containing catalysts. In general, such Cu-containing catalysts are made using ZnO, ZrO2 and Al2O3 precursors, such as soluble salts of the components such as copper nitrate, zinc nitrate, zirconyl nitrate, and aluminum nitrate and their simultaneous precipitation with a base such as sodium carbonate or bicarbonate.
Dehydrogenation can be used in reactions with alcohols. For example, dehydrogenation may be used to dehydrogenate methanol to give formaldehyde, ethanol to give acetaldehyde, 1-propanol to give propionaldehyde, isopropanol to give acetone, 1-butanol to give butyraldehyde, 2-butanol to give methyl ethyl ketone, isobutanol to give isobutyraldehyde, and also for dehydrogenating the isomeric primary and secondary pentanols, hexanols, heptanols, octanols, nonanols, decanols, undecanols and dodecanols to give the corresponding aldehydes and ketones respectively.
One such product formed from the dehydrogenation of ethanol includes ethyl acetate, which is commonly used as a solvent. The synthesis of ethyl acetate typically utilizes reactions between ethanol and acetic acid or the dehydrogenation of ethanol. Recently, interest in synthesizing ethyl acetate by dehydrogenating ethanol has increased because surplus ethanol feedstock can be used. Examples of catalysts and methods known in the art for forming ethyl acetate include the catalyst described in U.S. Pat. No. 7,091,155 B2 and the catalysts and methods disclosed in Chinese patent ZL Patent No. 92100590.3.
It would be desirable to provide dehydrogenation catalysts, methods for their manufacture and methods of use which exhibit higher catalytic activity than existing catalysts.